Model magnet studies

A design, construction, and testing program for model magnets is underway at Fermilab to evaluate alternatives in the development of small aperture magnets. The most thoroughly developed of these programs utilizes a set of model magnets based on the Tevatron quadrupoles and dipoles as a standard. These 7.6cm aperture model magnets, approximately 64cm long, have construction or material changes which are to improve quality and/or cost effectiveness. There are also superconductor parameter changes, as well as construction and materiai parameters, which impact or give insight into the choices of material specifications and construction parameters for the 5cm aperture model magnet series which are prototype candidates for the Superconducting Super Collider (SSC) ring magnets. The test program consists of performance test quenching of the windings at various temperatures until the cable critical current is reached. The quality of the magnetic field (Fourier coefficients) B(n) and quenching current is measured versus ramp rate, dB/dt, intensity, B, magnet temperature, and conductor parameters. The magnetization of the windings is measured as a function of these same parameters. There are also other special measurements made, i.e., deflection of coils. Two 5cm diameter aperture SSC candidate dipoles without iron are being prototyped: (a) a two layer, 6kA/turn version and (b) a single layer 10kA/turn model. In addition, there is a collaborative effort between KEK and FNAL in the development of a 10T (dipole, a longer range model) magnet program.